Warm Up Explain what happens when an acid & base combine. 1.The type of reaction 2.The products created Agenda Homework 1. Neutralization 2. Salt + water Begin Physics! – PPT/Notes on Energy Study for other classes!

Energy

What is Energy? Energy can be defined as the ability to do work. Energy is measured in Joules (J) J = 1 kg x m 2 or 1 Nm where N = 1 Newton s 2

Power The rate at which work is done. Power equals the amount of work done on an object in a unit of time. Power = Work = force x distance timetime

States and Forms of Energy Energy is found in different forms, such as light, heat, sound and motion. There are many forms of energy, but they can all be put into two categories: kinetic and potential.

Potential Energy Kinetic Energy All Energy Gravitation Potential Energy Elastic Potential Energy Chemical Potential Energy Nuclear Energy

Potential Energy Energy stored based on position or chemical composition The amount of potential energy associated with an object depends on its position.

What is Gravitational Potential Energy? Potential energy due to an object’s position P.E. = mgh m= mass (kg) g = gravity = 9.8 m/s 2 h=height (m) ALSO PE = weight X height

The rock climbers have gravitational potential energy. Circle the climber with the greatest potential energy. Use the height at the rock climber’s lowest foot. 1. PE = weight x height = 600 N x 4m = 2400 J PE = weight x height = 400 N x 4m = 1600 J 3. PE = weight x height = 600 N x 1m = 600 J 4. PE = weight x height = 400 N x 1m = 400 J

Elastic Potential Energy Is energy stored in objects by the application of a force. Compressed springs and stretched rubber bands are examples of stored elastic potential energy.

The energy stored in a stretched object, such as the trampoline, is elastic potential energy. Using 1 as the greatest, how would you rank the amount of elastic potential energy of the trampoline from greatest to least? 3 12

Chemical Potential Energy Is energy stored in the bonds of atoms and molecules. It is the energy that holds these particles together.

Nuclear Energy Energy stored in the nucleus of an atom; the energy that holds the nucleus together. The energy can be released when the nuclei are combined ( fusion ) or split apart ( fission ).

Fission or Fusion?

Nuclear Fusion and Fission Fusion: The sun combines the nuclei of hydrogen atoms in a process called fusion. Scientists are working on creating fusion energy on earth, so that someday there might be fusion power plants. Fission Nuclear power plants split the nuclei of uranium atoms in a process called fission.

Potential Energy Kinetic Energy All Energy Mechanical Energy Electrical Energy Radiant Energy Sound Energy Thermal Energy

Kinetic Energy Kinetic energy is the energy of motion The amount of kinetic energy depends on the mass and velocity of the moving object.

Determining Kinetic Energy E = ½ mv 2 E = energy ( Joules ) m = mass ( kilograms ) v = speed ( meters/sec. )

Mechanical Energy Can be both potential and kinetic energy Energy possessed by an object due to its motion Machines, bowling balls, hammers, a person running

Electrical Energy The movement of electrical charges like electrons in motion. These electrons in motion can create a magnetic field. Ex. Lightning, appliances, etc.

Thermal Energy The most common form of all energy Thermal energy is given off during most energy conversions The internal energy in substances the vibration and movement of the atoms and molecules within substances.

Radiant Energy Kinetic energy caused by the vibrations of electrically charged particles Energy in the form of electromagnetic waves, AKA light! We get light energy from the conversion of other sources of energy.

Sound Energy The movement of energy through substances in waves. Sound is produced when a force causes an object or substance to vibrate––the energy is transferred through the substance in a wave.

Energy Transformations Energy can be transformed from one type to another. In any energy conversion, some of the energy is lost to the environment as heat.

The seven types of energy… Chemical - gasoline, Light – flash light, Thermal – burner on a stove, Nuclear - sun, Mechanical - car, Sound – music on the radio, Electrical - lightning

Energy can be changed from one form to another Chemical energy in gasoline is changed to heat energy and then to mechanical energy in a car Chemical energy Thermal energy Mechanical energy